Re: [PATCH v5 00/12] GenieZone hypervisor drivers

["Yi-De Wu (吳一德)" <Yi-De.Wu@mediatek.com>]

On Fri, 2023-08-11 at 10:52 -0600, Rob Herring wrote:
>  	 
> External email : Please do not click links or open attachments until
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>  On Thu, Jul 27, 2023 at 03:59:53PM +0800, Yi-De Wu wrote:
> > This series is based on linux-next, tag: next-20230726.
> > 
> > GenieZone hypervisor(gzvm) is a type-1 hypervisor that supports
> various virtual
> > machine types and provides security features such as TEE-like
> scenarios and
> > secure boot. It can create guest VMs for security use cases and has
> > virtualization capabilities for both platform and interrupt.
> Although the
> > hypervisor can be booted independently, it requires the assistance
> of GenieZone
> > hypervisor kernel driver(gzvm-ko) to leverage the ability of Linux
> kernel for
> > vCPU scheduling, memory management, inter-VM communication and
> virtio backend
> > support.
> > 
> > Changes in v5:
> > - Add dt solution back for device initialization
> 
> Why? It's a software interface that you define and control. Make
> that 
> interface discoverable.
> 
> Rob

hi Rob,

Let me recap a bit about this as you might not notice our previous
response[1]. In order to discover our GenieZone hypervisor, there were
2 solutions being talked about, namely with dt or without dt.

The reasons we use dt now were listed in some previous mail thread[2].
I'll just copy the statements here for better sync-up.
- Although dt is for hardware, it's difficult to discover a specific
hypervisor without probing on all subsystem and thus pollute all of
other users as a consequence.
- The GenieZone hypervisor could be considered as a vendor model to
assist platform virtualization whose implementation is independent from
Linuxism.

In contrast to the solution with dt, what we were doing was probing via
hypercall to see whether our hypervisor exists.
However, this could raise some concerns about "polluting all systems"
even for those systems without GenieZone hypervisor embedded[3].

We're wondering if there's any specific implementation in mind from
your side that we could initialize our device in a discoverable manners
while not affecting other systems. We'll appreciate for the hint.

Regards,

Reference
1. 
https://lore.kernel.org/all/14c0381be38ea40fcd03104bff32bcaa09b920d3.camel@mediatek.com/
2. 
https://lore.kernel.org/lkml/ea531ba80db67cccb03ea173e714fe868f869e91.camel@mediatek.com/
3. 
https://lore.kernel.org/all/2fe0c7f9-55fc-ae63-3631-8526a0212ccd@linaro.org/

Regards,